| 摘要 |
PURPOSE:To operate stably an extraction circuit even if the ratio of carrier power to noise power is small, by providing a delay circuit in a part of the carrier extraction circuit of digital n-phase modulation receiving waves. CONSTITUTION:In the normal digital carrier extraction circuit consisting of n- multiplier circuit 402, resonator 403, slicer 404, 1/n frequency divider circuit 406 consisting of digital circuits, etc., pulse insertion circuit 406 consisting of differentiating circuit 502, delay circuit 503 and OR integrated circuit 504 is provided between slicer 404 and 1/n frequency divider circuit 406. For example, in case that one bit pulse is omitted in output waveform a of slicer 404 due to noise, waveform b differentiated by circuit 502 is inputted to circuit 504, and simultaneously, waveform b becomes waveform C delayed by one period (T time) in delay circuit 503 and is inputted to cirucit 504. Then, these waveforms are synthesized to become waveform d, and influences of noise are eliminated, and waveform d appears at terminal 505. |
